AN1224

Circuit design

5/10

of interest. Depending on the application, additional low frequency bypass capacitors

isolated with lossy elements (ferrite beads) may be required to prevent power supply noise

affecting gate and drain circuits. Circuit schematic is given in Figure 2, and layout in Figure 3

with component values in Table 2.

Figure 2.

Broadband power amplifier

Table 2.

Bill of material

Reference

Description

L1, L3, L4, L7

50

Ω transmission line

C1,C13

1000 pF chip capacitor

C2

39000 pF chip capacitor

C3

36 pF chip capacitor

R1

1 k

Ω resistor

C4, C6, C10

10000 pF chip capacitor

R2

1.2 k

Ω resistor

C5, C12

10 µF, 50V electrolytic capacitor

R3

240

Ω / 40 W resistor

C9, C11

1200 pF chip capacitor

C8

33 pF chip capacitor

C7

25-115 pF variable cap-arco trimmer

L2, L6

4:1 transformers, 10.7", 25

Ω.

Board

30mils, 2 ounces of copper,